Netatalk before 3.1.12 is vulnerable to an out of bounds write in dsi_opensess.c. This is due to lack of bounds checking on attacker controlled data. A remote unauthenticated attacker can leverage this vulnerability to achieve arbitrary code execution.
https://www.tenable.com/security/research/tra-2018-48
https://www.synology.com/security/advisory/Synology_SA_18_62
https://www.exploit-db.com/exploits/46675/
https://www.exploit-db.com/exploits/46048/
https://www.exploit-db.com/exploits/46034/
https://www.debian.org/security/2018/dsa-4356
https://github.com/tenable/poc/tree/master/netatalk/cve_2018_1160/
https://attachments.samba.org/attachment.cgi?id=14735
http://www.securityfocus.com/bid/106301
http://packetstormsecurity.com/files/152440/QNAP-Netatalk-Authentication-Bypass.html